Dynamic phoroptometer



DYNAMI C PHOROPTOMETER Filed May 24. 1926 3 Sheets-Sheet l Jan. 3l,1928. 1,657,601

C. E. H. ARMBRUSTER DYNAMI C PHOROPTOMETER Filed May 24, 1926 3Sheets-Sheet 2 lllllllllll lllllllllll C. E. H. ARMBRUSTER DYNAMICPHOROPTOMETER Patented Jan. 31, 19.28.

UNITED STATES CHARLES E. H. ARMBRUSTER, OF DENVER, COLORADO.

.P DYNAMIC PHOROPTOMETER.

Application lc-d May 24,

iii other object is to provide a4 series ot' accessible. quick operatingadjustn'lents `which will loe Within ready reach ot' the o pcratorduring the test.

another object is to provide a carrier 'for the test chart Which vvillallow t-he chart to oe readily placed at various distances and 1whichwill indicate to the operator the distance between the chart and thepatients eyes.

Still another object is to provide a test chart which will allow theoperators line oi vision to he substantially coincident with thepatients line of vision.

A 'tui-:ther object is to combine a readingI 't with a point ol lightfor use with a ali-ladder; rod so that 'the attention oit the patientmay he held andthe eyes placed in dynamic condition for making muscletests.

il still further object is to provide a mechanism which will project aloeam of light into either eye 'for the Maddox rod test while the othereye is at work and prevent the beams entering the remaining eye andconfusing the patient. rlhe means can he so constructed that should ithe desired for yeto-dnction tests, a beam can he project-l ed into hotheyes simultaneously.

Other ohjectsl and advantages reside in the detail constructioi'l oi theinventiol'i, `ihich is designed li'or simnlicity. economy, andcliiciency. These will become more apiiiarent from theflolloivingdescription.

Vin the f'clo detailed description ot the inve 'ence is had to theaccompanying drawings which form a part hereof. numerals refer to lilleparts in yall views ot the drawings and throughout the "ciption,

i. the drawings:

ff. l is a side elevation ott the complete illustrating' it in use. lnthis vica' the inoperative Lion of the light het; and reading charts isillustrated in lnolaen line.

192e. serial No. 111,256.

i 2 is a vertical section through the light hex and reading chart. l

3 is a face View of the light box and reading chart.

y Fig, 4 is a front elevation of thedevice. lhis view is taken lookingfrom the operators position and in it the reading chart in theinoperative position. i

Fig. 5 is" a detail View of the measuring tape attachment for measuringthe distance between the patients eye and the operators eye.

l? 6 is a detail View ot' one extremity ot' the lazy tongs employed forsupporting the light box illustrating the distance meter en iployedthereon.

Fig. 7 is a front elevation of the light hoi; with the secondary readingchart Aremoved.

Fig. S is a detail view of the tape ter-l ininal. i

Fig. S) illustrates in diagram the operation ot the lightbox;` at A thelight is heing projected into the patients lett eye; at B into the righteye; and at C into both eyes.

Fig'. 10 is a detail view illustrating' the operation of the lightshield on the light box. y

Fig. ll is a detail view of the method of carrying the primary readingchart. Y

Fig. 12 illustrates an alternate term oi. the primary reading chart inwhich the characters changeable While the` device is in operation andwhich alloivsthe operators eye to he at the `exact reading chartdistance.

Fig. 13 is an alternate :form of reading chart to be used in connectionwith the holder of Fig. ll.

le is a plan view oit the light box and reading charts oit' the formshown in Fig. l.

Fig. l5 is a. detail View illustrating a side elevation of the light boxpartially broken away to shoiv the use of the secondary reading chart ofFig.

The main supporting mechanism and traine ol' thin invention is similarto that disclosed in applicantls copending applicalion tor a macularretlectoscope, Serial No. i 111,257, led May 2li, 1926, and comprises amain traine 10, the extremities ont which, When the device is used as areflectosc'ope7 support suitable mirrors as illustrated in saidco-pending application lout-:Which ere not illustrateifl and not usedwhen the deviee is einployed as a dynamic optoineter or a phoroineter.

The main 'traine 10 is carried on a horizontal pivot 11 about which the.horizontal angle ot the device maybe adjusted by means ol an adjustingscrew 12. The pivot 11 is carried on a supporting bracket which iacarried on a vertical pivot in a collar 14 at the extreinity of aSupporting arm 15. The supportingr bracket 13 is locked .in iteI pivotin the collar 11- by means olf a clamp screw 16. lhe supportinl arin 15is carried in a Supporting arm bracket 17 vertically slidable upon acolumn 18. The upporting arm bracket 17 may be set at any desired heighton the column 1S by the manipulation ot alever 1Q. rlhe column 18 iscarried in a carriage 2O :slidably mounted between tracks 21 ot a baf-te'frame The base lframe E22 is pivoted at Q3 in a base Qet whichsuppi'irta the entire device lroin the wall ol' the rooni or any.suitable Supporting structure. Upon the main traine 1t). a trial traine25 is mounted, carrying a Series ol? the usual lens lraniesi QG andMaddox rod trames 2T. An adjustable forehead reist 3S is mount ed abovethe trial frame Q5 and an adjustable chin rest 29 is mounted therebelow.rlhe chin rest 29 is vertically movable on a chin rest 'frame 30 bymeans of an adjust-ing' wheel 31. The chin rest lrame 30 is horizontallyf -zlidable on the Supporting bracket 13. y

As thus lar described, the apparatus is Similar to that illustrated,disclosed and claimed in the Said Copendi'ng application. In thatapplication, the operation o'l" the 'a1-ions adjustments 'for the maintraine 1t), the forehead reiit 28 and chin rest 29 are described indetail.

Depending from the niain traine 10 ia a lazy tongs support 32, to which,a lazy tongs 33 is pivoted at 34, the lower member ot said tongs beingvertically Sliilable in a groove 35. The lazy tongs 33 tannin-isc aserie.;` olf crossed nienibere pivoted together by n'ieane ot eyelets9G. To accommodate dillerent depths et trial trames. the support 3Q maybe eecured at any deaired position alone' the nlaiu frame 10 in any pairof a Seriesoit holes llo. '.lhe lazy tonnet Il?, tcrminato in a lightbox trame 53T at a pivot 33S and in a Inroove 53S). i:)ivoted on thelight box frame 3T at all, a lee' -il which Fup ports a 4light box 12.The legi' il-l hasy a resilient iiirojecting tongue ell-5 which engageaa simila r tongue #il on the light box trame 3T so aS to Securelymaintain the le.;i +11 in the vertical or operative position. Then notin use, the 11 may be turned downwaixlly to the broken line position ofFig. 1.

A fixed indicating hand is formed on the light box traine 3T andindicates. on a igcale 1.6, the distance between the light bex hoeveeland the eye ol the patient. rlhe scale 1G is Secured to one ot themembers ot the lazy tongs 33 and Swings in an are about the pivot 38,from which the hand 15 extends. ae the lazy tongs ar-e extended orcontracted.

The leg ill torina the toi-ward 'tace ol` the light box 42 and isprovided with a relatively large aperture L1T inimediately in Alrontolfthe lilainent oit an electric lamp l-S 'which ie positioned Within thelight box. (lurrent if lied to the lamp ttl by means o i? a llexiblewire 97 which is passed through the eyelota fu ol' the lazy tongs. Theposition ot the lamp may be readily adjusted to bring' .its filament inalignment with the aperture Lt7 as it ia carried in a rotatable andvertically slidable Socket (i9 havingl a knurled iiuier hold TU. Thesocket may be locked in the adjusted position by means olE a nel: screwTl.

The rear iace ol the light bor; is dctaehable and .is illustrated indetail iu llie'. ll. lt maintained in place by ears, which engageopposite sides ot' the light box and have iudeutations :31 which entersimila indentatiom1 in the light box aides. The rear 'tace di) extendsiurivvardlvi above the top ot the light box and is provided a't eachaide ivith an inwardly turned flange iii? which slidably maintain arelatively small primary reading` chart 53 in place. ln the top ol' thelight box, an opening` l is lett through which light from the lamp loilluminatel the tace oi the chart- 53.

ln 'liront olf the aperture l?, au aperture plate 55 is niaintainedsuspended 'from a pivot 56, and may be locked in any desired poaitionabout its pivot, 51S by lucana` ol' a clamp :1ere/iv 58 which rides` in,a Slot ai) in the aperture plate and ia threaded into the legl '-11. Theaperture plate provided. im mediately in lront ot' the aperture l-T withtivo exceedingly Small periorations 5i'. These ].ieiif'orations arespaced eo that when the lin'ht box is a given distance Yl'roni thepatient, a beam ot light from the lamp in will Strike each ot' theymtients eyes.

ln liront olA the aperture plaie a sectorahaiied Shield (S0 is pivotedat (Sl. ln the Shield (Si), a notch (lf2 is formed io ride over thepivot ou. 'lhe depth ot the noli-h (3:3 acta to limit the arcuatemovement` ol' the L#hield (it) in one direction. The movi-nient in theother direction in limited by a reeil- :ient operating' arm tiel vwhichengagea a pro-- jeetinn' arm (i5 on the aperture plaie 535i. This,however. is but a teiuporanv Flop aiurc the armeA (la and (55 may hesprung. aa indi-- cated in broken line iu Fig. 11. to di -ennae'iz thearm 135 and allow the nhicld to move lo the position o1 Fie. 7. At thepoint when the shield (it) passes over the pei-tori:tions` 57, a slit-63 'toi-ined oi sufficient leueih io uncover both perlorations 57Siniultaneously,

hand perforation When the pivo lill) ldd cetacei extri-mity of' thenotch 62, as indicated in brolnm line in Fig. lt); Vand 'to :uncoverAthe lett hand perforation when ,the arms (5d and h5 are .ineugagen'ient, as indicated Ein solid line in the same ligure.

A secondary readingchartt- 6G is carried on kthe pivot ypins V56, (il,and a third pin (i7, immediately in front ofthe shield 60. In thereading .chart a slit y68 is formed which uncovers Aboth theperforations A57, the use of which will be later described.

Secured to the frame l is a tape line sups port 80 carrying; a springreel 8l arranged to reel a tape line The tape line passes .in front o tan iniflicator 79 and over an idler pulley The support 8O is formed ofrelatively thin sheet metal and has la tongue 83 bent to pass alongsideof the pulley 82. A cam 8st is arranged adjacent the pulley 82 and isactuated from a `cam lever S to force ,the tongue 8?) against the pulley82 and clamp the tape therebetween. `rlhe extrem ity of the tape line 73engages a meta-l terminal 74 which .is ott'set, as indicated at 75 atl'xed distances throughout its length. These vdistances correspond tothe differences in depths in dierent makes of trial frames rlheextremity .of the tape line 7 3 passes through an opening 7 6 in theterminal 74 and tern'iinatesin arectangular link 77. Should one of theshall-cwest of trial frames be in place upon the apparatus, the link 77is drawn along' the terminal 74C and placed in notches 7 8 formed intherotlset nearest the extremity of rthe terminal 7st. For vother depthsoit trial frames, the link engages other otisets on the terminal. Bythisarrangenient the operator does not. have to make a mentalcomputation for the depth of the trial frame. The reading -at theindicator 7S) on the tape 73 will be correct at all times. lheoperatornjiay retain the `tape reading` bv clamping the tape by means ofthe lever for future reference.` f

In use, the patient is placed behind the trfal frames and the chin andforehead rests adjusted to ,bring the line of sight'to the center of thelens frames 2G. The lazy tongs 33 are extended or contracted to bring'the readingchart at the proper distance for reading' lenses to beprescribed, the distance being quickly' determined by the hand -l andthe scale 4G. The patient is now dirccted to yread tho'primary reading;rchart 53 which is illuminated by the lamp 48 and the operator proceedsto make aV retinoscopic eX- aniination by means ofa retinoscope,illustrated in broken .linesat 72. ,Owing to the 'very small size of thechart 53, theoperators line of vision lwill be at all times atanegligible angle to the patients line of vision so that an accuratemeasure maybe made.

Thelsmall reading; chart 53 provided at its two upper corners withseries of .dotsm86- Should the operator, for a final checkydesire torthis purpose isillustrated at 87 in Fig.

13, which contains a sect1-on of reading' mat- J tei." 88 in each of`its corners. The section in each corner differs .in subject matter sothat .as ,thepatient audibly reads the chart, rthe operator will know atwhich portion of the chart the patient is looking` and may thenplaceliis retinoscope ,immediately behind that porti-ou Yso as todirectly align his line of vision with that of the patient.

The patient, in reading the matter on the primary chart 53 does notfocus truly ou the chart, since it is natural with all eyes to onlyfocus sufficiently to make the subject mattei' legible. The n'iajority1of eyes will focus beyond or at a `greater distance :than

-the reading,` chart, the distance between the chart and the true focusis known as accommodatve lag' and if not beyond ka given distance, it istermed normal lag. ,If the paftient is found to exceed this normal lag,he

requires additional lens strength to brianI his focus to the position ofnormal lag. ln

rare instances the pat'ents true focus may be in front of the chartwhich isyalso a sig nificant condition. j

"To find the patients true focal point, the operator with theretinoscope7 2, lirst takes a` position immediately behind the reading` chart 53and throws the retinoscopic light into the eye of the patient. Theoperator then slowly moves backwardly away from the chart and patient,until the true focal point is found. He then measures the distancebetween the patients eye and his, by means of the tape line 73, to findthe true focus. `The operator now compares the tape indication with themeasurementshown onA the scale 46 and immediately determines the`difference between the true focal point and thepatients fixation pointwhich gives him the amountI of accommodative lag'.

l't'is customary t-o refer to a patients readingv distance i u inches,therefore the scale elli is `graduated in inches. "Because of the easeand accuracy of 'the dioptrie system in add ing` and subtracting, thetape line 73 is zeraduated in dioptjers. These graduations, how ever,are optional and may be fixed to suit the personal habits of theoperator.

An alternate 'form of rear face for the light boX is illustrated at 89,'Fig'. 12. In this form, a mirror 90 `is placed at an angle to thereading matter, which is carried on a rotatable cube 91, so that theoperator may have his eye at the exact or even at a closer f distancethan the distance between the patient: and reading matter. In thisforni, the operator aligns his line of vision directly over the top ofthe inirror as illustrated in Fig. l5.

It is often ditiicult to keep a patients at tention concentrated on thematter on the reading.)` chart during a test, especially in the case ofchildren. The rotatable cube 91 helps to eliminate this difiiculty sincea riesl o l' dill'erent subjects and characters 92 may be placed on thesides ot' the cube and the cube rotated by means ot' a handle 93 tosuccessively bring the various characters and reading matter to theattention o'f the patient. il leal spring ill caused to bear upon arectangular' ratchet 95 on the cube sha-tt. to align the cube faces andhold it iu any desired position.

then using the apparatus a phorometer, the secondary reading chart Gtiis employed. Let us assume that one ot the Mad doX frames 2'( is placedbefore the left eye oli the patient, as indicated in diagram A in Fig.t). The shield (it) now brought to the solid line position of Fig. l()which allows a narrow beain ot light to be projected through the letthand perforation 57 through the Maddox rod and into the patients letteye, the upper part of the shield covering the primary reading chart 53.The usual inusele test is now made for the left eye. The Maddox rod isnow removed from the lett eye and placed before the right eye, asindicated at B, Fig. 9, and the shield (i0 moved to the broken lineposition of F ig. lO. This allows the light beam to project through theright hand perforation and the Maddox rod into the right eye of thepatient ior the muscle test thereon.

Should there be ditliculty in keeping the patients attention or havinghim concentrate and focus, he is directedto read the matter on theSecondary test chart G6 and when he reaches a position therein at theopening (SS. he is directed to inform the op erator ot the position inwhich he sees the red line of the leladdox rod.

For testing the powers oit cyclo-duction or the oblique muscle ol" theeye, a Maddox rod is placed belore each eye, as .sjiown at "il", Fig'.El, and the shield (il) moved to a position between the two positionsprevious ly described so that light beams will be projected through bothperfor-ations into both eyes. During all oi the muscle. tests, the samelight. is used as eui'iloyed to illuminate. the primary test chart fillbut the test chart concealral :trom the View o'l' the patient hy theshield G() and only the light from the perforations 5T is allowed toenter his eye.

lllhile a specitie torni oli the in'lprovenient has been described andillustrated herein, it isdesired to be understood that the saine may beVaried, within the scope of the apy pended claims, without departingfrom the spirit et the invention.

Having thus described the intention, what I claim and desire secured byLetters Patent is l. In a dynamic phoroptonieter haring a traine forcarrying test lenses bei'ore a pa' tient; an entendible bracket securedto said frame; a light box carried by said bracket.; a test chartcarried forward ot said light box; and a second test chart et relativelysmaller size projecting above said light boi; and adapted to beilluminated therel'rom.

2. ln a dynamic phoroptonleter having a. 'iframe 'iter carrying testlenses before a patient;` an extendihle braelret secured to said traine;a light box carried by said bracket; a test chart adapted to l iilluminated from said light box; and a series olf charmzters placed inlocalized relation adjacent the oorners oit said chart and indepemlentl'rom the remaining matter on said chart.

3. In a dynamic plioroptomeler haring a 'trame tor carrying test lensesbefore a patientg an oxtendible bracket secured to said traine; a lightbox carried by said bracket;

` a detachable back on said light box adapted to extend thereabore; anda test chart carried by said above-extending portion ol" sa id back andadapted to be illuminated 'lrom said light box.

Ll. In a dynanlie phoroptoineter having' a Ytraine tor carrying testlenses bclore a patient; an eXtendible bracket secured to .said traine;a light box carried by said ln'aeliet: a detachable back on said lightbox adapted to extend tliereaboye; a test chart carried by saidabove-extending portion ol said back and adapted to be illruninated fromsaid light bolt; and ears formed on said bark and adapted to clamp saidligllt. box to maintain said baclr in place.

5. In a dynamic phoroptoiheter a single light source; means providedwith two rela tively sniall, horizontally aligned, spaecal apartapertures adapted to be arranged between said single light source andthe cy s of a patient, the spacing ot said apertures being such that oneo'll .said apertures will be in alignment between saidsinglelightsourcoand one of the. patients eyes while the other aperture is in alignmentbetween said single light source and the other ol' the patients eyes.

t. lu a dynamic i)horoptomeler :l single light source, means` providedwith tufo relatively small, horizontally aligned, spared apartaperturesadapted to be arranged between said single light source and theet .i oit a patient, each ot said apertures Ianni: in alignment betweensaid light source and one o't the patients eyes; and a shield hav ing anopening arranged to open either one or both ot said apertures asdesired. y

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Y. ln a dynamic phoroptoineter a light source; means provided with tworelatively small apertures arranged between said light source and apatient, each of said apertures i: being in alignment between said lightsource and one of the patients eyes; means for closing either one orboth of said apertures desired; and a reading chart surrounding saidapertures.

tl. ln a dynamic phoroptometer; a light source; a light boi; surroundingsaid light source; and provided with apertures in alignment with theeyes of a patient; and a pivot-ed shield haif'ing an opening adapted toopen either one or both of said apertures as desired.

ln a dynamic phoroptometer for use in examining the eyes of a patient, alight boit; a chart adapted to be illuminated from said lightboiz, saidlight box having two apertures each adapted to allow light to flow fromsaid light boi; into one of the patients eyes; a movable shield adaptedto open either one or both of said apertures, said shield arrangei'l toshut olf the view ot said te chart from said patient when said aperturesare open. i

lt). ln a dynaniic phoroptometcr means for projecting a beam of lightfrom a light source through a Maddox rod into a patici .ye comprising anaperture plate adjustably mounted before said light source; aiierlforation in said plate in alignment be tween said light source andone of the patientls eyes; a second perforation in said plate inalignment between said light source and the other of the pat-ients eyes;and a movable shield adjacent said aperture plate and having an openingarranged to open either one or both of said perforations.

ll. l'n a dynamic phoroptometer means for projecting a beam of lightfrom a light source through a Maddox rod into a patients eye comprisingan aperture plate adjustably mounted before said light source; aperforation iu said plate inl alignment between said light source andone of the paticuts eyes; a second perforation in said 'plate inalignn'ient between said light source and the other of the patientseyes; a mov able shield adjacent said aperture plate and having anopening arranged to open either one or both of said perforations; andmeans for liniiting the movement of said shield when said opening isover either one of said perfor-ations.

12in a dynamic phoroptometer means for projecting a beam of light from alight source through a Maddox rod into a patients eye comprising anaperture plate adjust-ably mounted before said light source; a

perforation in said plate in alignment between said light source and oneof the patients eyes; a second perforation in said plate in alignmentbetween said light 'source and the other of the patients eyes; a shieldpivoted adjacent said aperture plate and having an opening arranged toopen either one or both of said perforations; means for limiting themovement of said shield when said opening is over either one of saidperforati-ons, said means comprising an arm on said aperture platearranged to engage a projection on said shield; and a slot in saidshield adapted to engage the pivot of said aperture plate.

13. In a dynamic phoroptometer means for projecting a beam of light froma light source through a Maddox rod into a patients eye comprising anaperture plate ladjustably mounted before said light source; a lAerforation in said plate in alignment between said light source and oneof the patients eyes; a second perforation in said plate in alignmentbetween said light source and the other of the patients eyes; a movableshield adjacent said aperture plate and having an opening arranged toopen either one or both of said perforations; and a test chart securedbefore said aperture plate and having an opening adapted to expose bothsaid apertures.

let. ln a dynamic phoroptometer having a main iframe supporting a testframe and a test chart, means for varying the distance between said testchart and said test frame comprising an entendible support attached toVsaid main frame and carrying said test chart, said support comprising aseries of pivoted links; and means for varying the point of attachmentof said entendible frame to accommodate different depths of test frames.

l5. In a dynamic phoroptometer having a test frame and means forindicating the distance between an operator and his patient; means foraccoiiinting for ditl'erent depths in said ytest frame in themeasurement of said tape comprising a terminal for said tape; and meanson said terminal for securing the tape extremity at dillcrent relativelongitudinal positions thereon.

16. ln a dynamic phoropton'ieter having a light box; a back on saidlight box extending above the top thereof, there being an opening insaid top and a test chart carried by said above extending portion ofsaid back so as to be illuminated by the light through said opening.

In testimony whereof, I afiix my signature.

CHARLES E. H. ARMBB-USTER.

